"Sure it was." You retort sarcastically.
"No, really! She's been stealing money for years! I'll pay you
back! Just tell me how much she took! I'm sorry for what she did to
you!" She really seems sincere.
Suddenly, an evil idea strikes you. You could tell this girl, assuming
she isn't Kristen, that her twin stole more money than she did. That
way, you could make a profit. But if your price is too ridiculous,
she'll realize it.
"It was my evil twin sister!" She yelps.